Diabetes Mellitus has been treated for many years by insulin injection. Three recent advances are changing diabetes care: The Insulin Pump, new insulin formulas for Multiple Dose Injection, and Inhaled Insulin. These are discussed below:
THE INSULIN PUMP: The invention of the insulin pump revolutionized diabetes care. It is a battery-powered device about the size of a pager. It contains a cartridge of insulin and pumps the insulin through a flexible tube into the patient via an “infusion set”, which is a small plastic needle or “canula” fitted with an adhesive patch. The invention of the pump makes it possible to adopt a typical insulin regimen as follows: Basal Insulin is injected slowly and continuously at a rate that can be programmed to change multiple times during the day (about 4 or 5 changes per day is common). Between the changes, the Basal Insulin Rate of infusion is constant. The constant periods are called “intervals”. Additionally, boluses of insulin can be injected on command by the patient. There are two main types of boluses:
Meal Boluses are infused just before a meal in an amount, proportional to the glycemic effect of the meal. This is generally proportional to the number of grams of carbohydrate in the meal. The proportionality constant is a personalized number called the Carbohydrate-to-Insulin Ratio, CIR. It is used as follows:Meal Insulin Bolus=(grams of carbohydrates in the meal)/CIR  (1)
This calculation is generally performed by the patient, but there are pump models that can store the patient's CIR in memory and require only the grams of carbohydrate in the meal as the input.
Correction Boluses are infused immediately after a Blood Glucose test has been performed; the amount of the correction bolus is proportional to the error in the blood glucose concentration from the patient's personalized Target Blood Glucose. The proportionality constant is a personalized number called the Correction Factor, CF. It is used as follows:Corrective Insulin Bolus=(Blood Glucose concentration−Target)/CF  (2)
There are two types of Corrective Bolus, each with a different Target:
Time-Boundary Corrective Insulin Boluses are administered in a fasting state at the end of a time interval.
After-Meal Corrective Boluses are administered from one to five hours after a meal, most often within the time interval.
Recently, pump manufacturers have been incorporating digital features in their pumps that make treatment easier. Some pumps can store the values of CF and Target and require only the Blood Glucose Concentration (BG) as input. Among these new digital features is the “Insulin-On-Board” feature. This feature mathematically models the amount of insulin still in the body at a given time after a bolus and recommends reductions to the boluses accordingly. This feature makes After-Meal Corrective Boluses more safe and practical.
MULTIPLE DOSE INJECTION (MDI): Advances are being made in developing different types of insulin. Some are very long acting and non-peaking. The long-acting insulin can be injected as infrequently as once per day in a regimen very similar to a pump patient's basal insulin regimen. Injections of rapid-acting types of insulin can be given as meal and correction boluses. The two types together act as a system. These insulins are available in portable “pens” (named for their resemblance to writing implements). The pens have been mated with BG meters in “kits” in which the devices communicate so that the combined memory is stored in one of the two devices in the “kit”.
INHALED INSULIN: Inhaled insulin delivery systems are under development for short-acting insulin. It is expected that the inhalers will be combined with BG meters into “kits” like the ones used for MDI, then the present invention will be able to handle inhaled insulin in the same manner. This development is expected in the future.
The nature of diabetes care is very quantitative. Ironically, the proliferation of numbers makes the use of lengthy algorithms on pocket calculators too time-consuming and therefore prohibitively expensive. The majority of endocrinologists, therefore, use experience-based subjective methods. In the interest of providing greater subjective feel for the case at hand, endocrinologists often use the numbers to simply help them discern trends; then treat the trends. For instance, they commonly view the blood glucose (BG) scatter charts and printouts to discern trends by such subjective means as the visual density of dots on the BG scatter chart and the relative location of the areas of highest density. They translate these trends into insulin dose changes using their experience.
Experienced-based and subjective methods are often not uniform from one practitioner to the next. Additionally, there is a shortage of endocrinologists and other diabetes specialists. Accordingly, the management of diabetes is done in a disorganized manner by clinicians of widely varying degrees of expertise. The result is that control of diabetes in most patients, while satisfactory, is not optimal. As a result of sub-optimal BG control, the course of diabetes can include complications involving all body systems. These complications are associated with premature mortality and are associated with a cost, which amounts to 19% of the health dollars to care for 6% of the population.